The Palace of Westminster is the meeting place of the Parliament of the United Kingdom and is located in London, England. It is commonly called the Houses of Parliament after the House of Commons and the House of Lords, the two legislative chambers which occupy the building.
 
The palace has a protected silhouette which means you can't build anything behind which could interfere with it. When we design building in London we have to test this including calculation the curvature of the earth to make sure we don't pop up.